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1.
Successful subtraction of instrumental background variations has permitted spectral analyses of two-dimensional measurement arrays of granulation brightness fluctuations at the center of the disk, arrays obtained from Stratoscope I, 1959B-flight, high-resolution frames B1551 and B3241.
  1. RMS's, uncorrected for instrumental blurring, are 0.0850 of mean intensity for B1551 and 0.0736 for B3241, somewhat higher than other determinations. These between-frame and between-investigation differences probably result from a combination of calibration errors, frame resolution differences, and, most likely, granulation pattern differences.
  2. Significant variations over each array of mean intensities and RMS's, determined for sub-arrays with dimensions in the 2500–10000 km range, indicate spatial brightness and RMS variations larger than the ‘scale’ of the granulation pattern, supporting a turbulent interpretation of photospheric convection.
  3. One-dimensional power-spectra shapes provide objective and discriminating criteria for determining granulation pattern differences and, possibly, frame resolution.
  4. Two-dimensional power spectra show small, essentially random deviations from axial symmetry which lie almost entirely within the 50% confidence limits.
  5. Spectral densities and fluctuation power spectra, computed from the two-dimensional power spectra and corrected for instrumental blurring, noise, and blemishes, have a useable radial wavenumber range nearly double that of earlier Stratoscope I analyses.
  6. Corrected RMS's obtained from the corrected fluctuation power spectra, 0.145 ± 0.046 for B1551 and 0.136 ± 0.048 for B3241, depend critically on the accuracy of the correction.
  7. The spectra's wavenumber range includes the granulation-fluctuation-producing domain but not the Kolmogoroff domain of turbulence spectra.
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2.
An analysis of the data concerning high-velocity stars from Eggen's catalogue aimed at a determination of the approximate slope of the mass function for the spherical component of our Galaxy, and at estimating the local circular velocity, as well as the local rotation velocity, as by-products, has been performed. Our conclusions are that:
  1. A linear dependence of the mass on the radius is very likely;
  2. the value of the limiting radius is most likely equal to (40±10) kpc;
  3. the two local velocities are approximately equal to each other, being both equal to (230±30) km s?1;
  4. the local escape velocity appears to be most likely equal to (520±30) km s?1;
  5. the total mass of a corona, obtained in this way, is (5±1)×1011 M ⊙.
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3.
From a comparative study between stellar and gas data it is seen that turbulent and hydrodynamic motions in the Galaxy are common to both types of materials:
  1. Galactic clusters have sizes and intrinsic dispersions compatible with the modified form of the Kolmogorov law seen in molecular clouds: undimensional velocities σ(km s?1)=0.54d 0.38 (pc). This indicates that ‘typic’ clusters were born from ‘typic’ dark clouds as these of the Lynds's catalogue (diametersd<10 pc, dispersions σ<1.5 km s?1 hydrogen densitiesn H>200 atom cm?3). These clouds have mass enough to form galactic clusters (1000–3000M ⊙).
  2. The cluster formation is related to the supersonic range of the Kolmogorov relationship σ(d>1 pc) while the AFGKM stars are related to the subsonic range of the same relationship σ(d<0.3 pc), the intermediate transition zone is probably related to OB stars and/or trapezia.
  3. The effects of the magnetic fields in the clouds are also discussed. It seems to be that in the clouds the magnetic energy does not exceed the kinetic energy (proportional toσ 2(d)) and that this determinates the freezing criteria. The hypotheses introduced here can be checked with 21 cm Zeeman splitting.
  4. Low-density globular clusters are also coherent with the Kolmogorov relationship. Some hypotheses about their origin and the type of clouds where they were born are discussed. This last part of the study lets open the possibility of further studies about evolution of globular clusters.
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4.
The properties of rapidly changing inhomogeneities visible in the H and K lines above sunspot umbrae are described. We find as properties for these ‘Umbral Flashes’:
  1. A lifetime of 50 sec. The light curve is asymmetrical, the increase is faster than the decrease in brightness.
  2. A diameter ranging from the resolution limit up to 2000 km.
  3. A tendency to repeat every 145 sec.
  4. A ‘proper motion’ of 40 km/sec generally directed towards the penumbra.
  5. A Doppler shift of 6 km/sec.
  6. A magnetic field of 2100 G.
  7. A decrease in this field of 12 G/sec. This decrease is probably related to the flash motion.
  8. At any instant an average of 3–5 flashes in a medium-sized umbra. A weak feature often persists in the umbra after the flash. This post-flash structure initially shows a blue shift, but 100–120 sec after the flash, it shows a rapid red shift just before the flash repeats.
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5.
The galactic distribution of pulsars and shell remnants of supernovae (SN) as investigated on the basis of newly-estimated parameters. Special attention was paid to taking into account all possible selection effects and an attempt was made to reveal a statistically-pure ensemble of objects. On the basis of this ensemble we studied the radial andz-distribution of pulsars and supernova remnants (SNR).It is shown that the radial distribution of both objects is considered to have an annular structure with the maximum surface density at a distance of 4.5–5.3 kpc (if the distance of the Sun from the galactic centre is assumed to be equal to 8.5 kpc). The scle-height of the progenitors of SNRs is not more than 110 pc and only 15% of the SNRs, whose progenitors may also be massive runaway stars, are situated at 300 pc. The mean application of the pulsars is not more than 300 pc which agrees with the hypothesis about the genetic connection with type-II SN outbursts at the kinematic aget k5×106 yr and thez-component of spatial velocity beingV z=120 km s–1.The possible precursors of type-I SNRs by the shape of their radial distribution in late spirals and the various model calculations given in the literature, are also discussed.  相似文献   

6.
Evening twilight airglow emissions of OH (7,2) band and Li 6708 Å are observed by Dunn-Manring type photometer and following important results are obtained.
  1. Intensity of OH (7,2) and Li (6708 Å) decrease exponentially during evening twilight period.
  2. OH (7,2) band covaries with Li (6708 Å) during evening twilight period.
  3. Empirical equations of OH (7,2) band with time is obtained.
  4. Possible explanations of such type of variations is also presented.
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7.
The radio emission of a selected number of solar active regions has been investigated with high angular resolution at two frequencies: 10 and 17 GHz. By comparing the results of the two observations the following conclusions can be drawn:
  1. The brightness temperature distribution of an active region is often composed of very bright cores of small dimension (angular extent θ?20″) imbedded in extended halos of lower brightness.
  2. The radio emission of such structures as well as the degree of polarization can be explained with a thermal process. The halos can originate by pure thermal bremsstrahlung while in the case of the very bright cores found at 10 GHz (brightness temperature T b?1–9 × 106K) the emission at the harmonics of the gyrofrequency is needed.
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8.
Four consecutive years of a quasi-continuous survey of the solar Lα line are presented. Absolute calibration and aging correction are evaluated producing higher quality measurements which are:
  • -the total Lα flux,
  • -the central Lα flux,
  • -the blue wing flux at 0.33 Å from the center,
  • -the slope of the blue wing at the same location.
    • Empirical laws are deduced from this large amount of data giving a relation between these different parameters and the flux integrated over the whole line. Furthermore, other empirical laws are obtained between the total Lα flux and two solar activity indices. These relations give a possibility of evaluating the solar Lα flux even when no observation is available and, as previously found by Prinz (1974), show that to a first approximation the solar Lα flux is composed of a quiet and of an active component. The active component changes with the 27 days period; the quiet one with the 11 yr solar cycle.  相似文献   

    9.
    We present a broad range of complementary observations of the onset and impulsive phase of a fairly large (1B, M1.2) but simple two-ribbon flare. The observations consist of hard X-ray flux measured by the SMM HXRBS, high-sensitivity measurements of microwave flux at 22 GHz from Itapetinga Radio Observatory, sequences of spectroheliograms in UV emission lines from Ov (T ≈ 2 × 105 K) and Fexxi (T ≈ 1 × 107 K) from the SMM UVSP, Hα and Hei D3 cine-filtergrams from Big Bear Solar Observatory, and a magnetogram of the flare region from the MSFC Solar Observatory. From these data we conclude:
    1. The overall magnetic field configuration in which the flare occurred was a fairly simple, closed arch containing nonpotential substructure.
    2. The flare occurred spontaneously within the arch; it was not triggered by emerging magnetic flux.
    3. The impulsive energy release occurred in two major spikes. The second spike took place within the flare arch heated in the first spike, but was concentrated on a different subset of field lines. The ratio of Ov emission to hard X-ray emission decreased by at least a factor of 2 from the first spike to the second, probably because the plasma density in the flare arch had increased by chromospheric evaporation.
    4. The impulsive energy release most likely occurred in the upper part of the arch; it had three immediate products:
    1. An increase in the plasma pressure throughout the flare arch of at least a factor of 10. This is required because the Fexxi emission was confined to the feet of the flare arch for at least the first minute of the impulsive phase.
    2. Nonthermal energetic (～ 25 keV) electrons which impacted the feet of the arch to produce the hard X-ray burst and impulsive brightening in Ov and D3. The evidence for this is the simultaneity, within ± 2 s, of the peak Ov and hard X-ray emissions.
    3. Another population of high-energy (～100keV) electrons (decoupled from the population that produced the hard X-rays) that produced the impulsive microwave emission at 22 GHz. This conclusion is drawn because the microwave peak was 6 ± 3 s later than the hard X-ray peak.
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    10.
    Celebrating the diamond jubilee of the Physics Research Laboratory (PRL) in Ahmedabad, India, we look back over the last six decades in solar physics and contemplate on the ten outstanding problems (or research foci) in solar physics:
    1. The solar neutrino problem
    2. Structure of the solar interior (helioseismology)
    3. The solar magnetic field (dynamo, solar cycle, corona)
    4. Hydrodynamics of coronal loops
    5. MHD oscillations and waves (coronal seismology)
    6. The coronal heating problem
    7. Self-organized criticality (from nanoflares to giant flares)
    8. Magnetic reconnection processes
    9. Particle acceleration processes
    10. Coronal mass ejections and coronal dimming
    The first two problems have been largely solved recently, while the other eight selected problems are still pending a final solution, and thus remain persistent Challenges for Solar Cycle 24, the theme of this jubilee conference.  相似文献   

    11.
    Based on the developed method of jointly using data on the magnetic fields and brightness of filaments and coronal holes (CHs) at various heights in the solar atmosphere as well as on the velocities in the photosphere, we have obtained the following results:
  • The upward motion of matter is typical of filament channels in the form of bright stripes that often surround the filaments when observed in the HeI 1083 nm line.
  • The filament channels observed simultaneously in Hα and HeI 1083 nm differ in size, emission characteristics, and other parameters. We conclude that by simultaneously investigating the filament channels in two spectral ranges, we can make progress in understanding the physics of their formation and evolution.
  • Most of the filaments observed in the HeI 1083 nm line consist of dark knots with different velocity distributions in them. A possible interpretation of these knots is offered.
  • The height of the small-scale magnetic field distribution near the individual dark knots of filaments in the solar atmosphere varies between 3000 and 20000 km.
  • The zero surface separating the large-scale magnetic field structures in the corona and calculated in the potential approximation changes the inclination to the solar surface with height and is displaced in one or two days.
  • The observed formation of a filament in a CH was accompanied by a significant magnetic field variation in the CH region at heights from 0 to 30000 km up to the change of the predominant field sign over the entire CH area. We assume that this occurs at the stage of CH disappearance.
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    12.
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    13.
    This paper is primarily concerned with the questions of models and the mechanisms of radio emission for pulsars, the polarization of this radiation and related topic. For convenience and to provide a more complete picture of the problems involved, a short summary of the data on pulsars is also given. Besides the introduction, the paper contains the following sections:
    1. Some Facts about Pulsars.
    2. The Astrophysical Nature of Pulsars.
    3. Coherent Mechanisms of Radio Emission from Pulsars.
    4. Models of Pulsars: Magnetic, Pulsating White Dwarfs and Neutron Stars.
    5. The Polarization of the Radio Emission from Pulsars.
    6. A Synthesized Model of Pulsars — Magnetic, Pulsating and Rotating Neutron Stars.
    7. Concluding Remarks.
      相似文献   

    14.
    We have reanalysed a homogeneous catalogue of shell-type supernova remnants and we find that the radio data are consistent with a birthrate of one in 22±3 yr. Our approach is based on the secular decrease of surface brightness of the historical remnants whose ages are precisely known. The abovementioned birthrate is significantly higher than most previous estimates which range from one in 50–150 yr, and is consistent with the supernova rate in our galaxy derived from historical observations, as well as with recent estimates of the pulsar birthrate.  相似文献   

    15.
    The Transition Region and Coronal Explorer (TRACE) gave us the highest EUV spatial resolution and the Ramaty High Energy Solar Spectrometric Imager (RHESSI) gave us the highest hard X-ray and gammaray spectral resolution to study solar flares. We review a number of recent highlights obtained from both missions that either enhance or challenge our physical understanding of solar flares, such as:
    1. Multi-thermal Diagnostic of 6.7 and 8.0 keV Fe and Ni lines
    2. Multi-thermal Conduction Cooling Delays
    3. Chromospheric Altitude of Hard X-Ray Emission
    4. Evidence for Dipolar Reconnection Current Sheets
    5. Footpoint Motion and Reconnection Rate
    6. Evidence for Tripolar Magnetic Reconnection
    7. Displaced Electron and Ion Acceleration Sources.
      相似文献   

    16.
    A typical concentric ellipse multiple-arch system was observed in the solar corona during the February 4, 1962 eclipse in New Guinea. The following results have been obtained from analysis of a white-light photograph taken by N. Owaki (see Owaki and Saito, 1967a).
    1. The arches are composed of four equidistant components, elliptical in shape, and almost concentric with a prominence at the common center of the ellipses.
    2. The prominence and arch system appears to be the lower region of a helmet-shaped streamer.
    3. The widths of the arches are observed to increase with height.
    4. Analysis was made in the light of three models for the coronal structures that could lead to the observed arches: (a) rod-like concentrations of electrons; (b) tunnel-shaped elliptical shells of electrons; and (c) dome-like ellipsoidal shells of electrons. Electron densities are derived for the models, and the dome-like model is excluded as a possibility for arch systems exhibiting a coronal cavity.
    5. The scale height in the arch-streamer region is found to be almost the same as that of the K-corona, suggesting equal temperatures, density distributions, etc. in each region.
    6. There is a dark space (a coronal cavity) between the innermost arch and the prominence. The brightness of this cavity is 1/5 that of the adjacent arch. It is 3% brighter than the background corona of the arch-streamer system.
    7. A comparison is made between the deficiency of electrons in the coronal cavity and the excess of electrons in the prominence. It is found that the ratio of the excess to the deficiency lies between 0.9 and 40.
    8. A comparison between the electron efflux from the ‘leaky magnetic bottle’ possibly formed by rod-shaped coronal arches and the electron influx into those arches from the chromosphere leads us to the conclusion that the rod model is probably valid and that spicules appear to be an adequate supply for the electrons observed in the arches. The tunnel model may be valid, but in that case spicules are probably not the sources of the electrons observed in coronal arches.
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    17.
    Coordinates of polar faculae have been measured and processed using daily photoheliograms of the Kislovodsk Station of the Pulkovo observatory with the final goal of studying their latitude distribution during the solar cycles 20–21. The results obtained are as follows:
    1. The first polar faculae emerge immediately after the polarity inversion of the solar magnetic field at the latitudes from 40° to 70° with the average ?-55°.
    2. The zone of the emergence of polar faculae migrates poleward during the period between the neighbouring polarity inversions of the solar magnetic field. This migration is about 20° for 8 years, which corresponds to a velocity of 0.5 m s-1.
    3. The maximum number of polar faculae was reached at the activity minimum (1975–1976).
    4. The last polar faculae were observed in the second half of 1978 at the latitudes from 70° to 80°.
      相似文献   

    18.
    The fine structure of a sunspot is studied on a series of photographs obtained during the third flight of the Soviet Stratospheric Solar Station. The main results are as follows:
    1. The micro-photometer tracings on the frames show extremely high Rayleigh resolution of small elements, the smallest distances being near to the theoretical limit. The half-widths of the brighter elements are given in Tables III and VI. The corrected brightness of umbral dots has large dispersion.
    2. The dimensions of the smallest dots are equal to the diffraction image of bright points. So the real radii of these objects are smaller than 150km, which is consistent with opaque models of sunspot umbra.
    3. The penumbra and umbra structure (dark and bright objects) is in good agreement with the picture of magnetic field splitting in a system of magnetic ropes giving rise to the magnetic arcs in the chromosphere and corona. Only in the umbra do we meet the large scale continuities.
      相似文献   

    19.
    Shock remagnetization is a significant mode of alteration of the intensity and direction of magnetization in planetary crustal rocks subjected to the dynamic and thermochemical effects associated with meteorite impact. Shock remagnetization will take place almost instantaneously during and following the transient shock episode, and over longer times depending on residual temperature effects associated with shock heating and the production of impact melt. Remagnetization will follow certain demagnetization effects. The following transitions and residual effects will result in remagnetization of planetary crustal material:
    1. First order reversible crystallographic transitions in bodycentered cubic iron-nickel alloys.
    2. Second order Curie temperature transitions in face-centered cubic iron-nickel alloys.
    3. Shock induced uniaxial anisotropy due to magnetoelasstic coupling of magnetic vectors to the shock wave.
    4. Shock melting of iron containing silicates.
    5. Subsolidus reduction and FeO decomposition.
    6. Partial ther moremanence due to post-shock temperature.
    7. Total thermoremanence due to post-shock temperature.
    8. Production of a superparamagnetic distribution of iron which is sensitive to surface temperature fluctuation.
    9. Thermal effects in metal and alloy phases.
    Lunar breccia and soil samples are generally more reduced than crystalline rocks and some of th's reduction is subsolidus probably associated with the transient thermal effects due to meteorite impact in teh porous reglith.  相似文献   

    20.
    Photoelectric measurements of Doppler shifts of various Fraunhofer lines obtained with the Capri magnetograph were analysed. The height dependence of the supergranular and oscillatory motions, as well as the two dimensional structure of these velocity fields is investigated. The most interesting results are the following:
    1. The oscillatory and supergranular motions are still clearly present in very deep photospheric layers as detected e.g. by means of the Ci line at 5380.3 Å.
    2. Whereas the vertical motions (both of oscillation and supergranulation) increase with height, the horizontal component of the supergranular flow is found to be decreasing slightly.
    3. Aperiodic horizontal motions are observed in the photospheric layers, which are probably connected with the process of excitation of the oscillatory field.
    4. There is no simple way of describing the oscillatory field in terms of independently oscillating ‘cells’, since the two-dimensional pattern changes its appearance drastically already in a fraction of one oscillation period.
    5. The correlation obtained by previous observers between vertical stationary motions, the chromospheric network and magnetic fields in particular is confirmed.
      相似文献   

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